Field of the Invention
This invention relates to the sorting of objects or products such as poultry during travel along a predetermined path suspended by load carriers from a conveyor.
Conveyor associated weight sorting systems to which the present invention pertains, are already well known as disclosed for example in U.S. Pat. No. 4,148,397. In such weight sorting systems, poultry shackle types of load carriers are suspended in uniformly spaced relation to each other from an overhead conveyor. The carriers are elevated onto a fixed track at a weighing station to gravitationally unload of the conveyor chain which continues to pull the carriers through the weighing station with the gravitational loading transferred to the track by load supporting track wheels on the carriers. Loading platforms are mounted in alignment along the track for limited vertical displacement when loaded above preset weight limits as determined by the setting of scale beam types of detectors respectively connected to the loading platforms. These detectors generate load release signals applied to a load release mechanism by means of which products such as poultry outside of a preset weight range are dropped from the conveyor line. Two loading platforms are therefore utilized with detectors set to drop such loads so that only loads within the preset weight range continue beyond the weighing station for processing.
In the foregoing type of weight sorting system, the loading Platforms associated with a single conveyor line are longitudinally spaced from each other and aligned with uniformly spaced carrier track wheels to sequentially detect loading above load limits as aforementioned. Accuracy of load limit detection depends on the speed of the conveyor and the spacing between carriers which determine the duration of loading of each loading platform. Apparently because the load limit detecting action involves gravitational displacement of the loading platform out of horizontal alignment with a fixed track, detection accuracy is unacceptably lowered when the loading duration is decreased below some minimum time period. Therefore, the minimum loading duration imposes a dimensional restriction on the platform length, the conveyor speed and the carrier spacing. While it would be obvious to increase the length of the loading platforms to insure accuracy, any increase is limited by the geometrical restriction necessary to obtain load limit detection of each carrier one at a time without interference. Thus, the length of the loading platform was heretofore made less than the spacing between carriers by an amount required to accommodate swing of the suspension links connecting the carriers to the conveyor thereby avoiding any simultaneous loading of a platform by two carriers.
It is therefore an important object of the present invention to provide a weight sorting system for a single conveyor line operated at a production rate exceeding the maximum rate above which acceptable load lLmit detection accuracy was heretofore deemed possible.
A further object of the invention is to provide a weight sorting system having acceptable load limit detection accuracy for a given conveyor speed despite the use of additional load carriers decreasing the spacing between successive carriers on a single conveyor line, the use of additional carriers on the same conveyor line being desirable for functions unrelated to the weight sorting operation, such as product grading.
Other objects of the present invention relate in general to providing an acceptably accurate, weight sorting system for a single conveyor line with greater design flexibility to meet various product processing requirements.